Giant Extrinsic Spin Hall Effect in Platinum-Titanium Oxide Nanocomposite Films

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Spin Hall effect enables current-induced magnetization manipulation for spintronic devices.
• Existing spin Hall materials face limitations due to low spin Hall angles or high resistivity, hindering low-power applications.
• Development of advanced spin Hall materials is crucial for next-generation memory and logic devices.

Purpose of the Study:

• To investigate Pt(TiO2) nanocomposites as novel spin Hall materials.
• To achieve a giant spin Hall effect combined with low resistivity for enhanced device performance.
• To explore the potential of these materials in low-power magnetic random access memory and logic devices.

Main Methods:

• Fabrication of Pt(1-x)(TiO2)x nanocomposite films.
• Utilized ferromagnetic resonance, spin pumping, and inverse spin Hall effect experiments.
• Estimated spin Hall angle in yttrium iron garnet/Pt(1-x)(TiO2)x heterostructures.

Main Results:

• A giant spin Hall angle of 1.607 ± 0.04 was achieved in Pt0.94(TiO2)0.06 nanocomposite.
• This represents an order of magnitude increase compared to pure Pt thin films (0.051 ± 0.002).
• The enhancement is attributed to side-jump effects induced by TiO2 impurities.

Conclusions:

• Pt(TiO2) nanocomposites offer a promising new class of spin Hall materials.
• These materials exhibit a giant spin Hall effect, low resistivity, and semiconductor process compatibility.
• Findings pave the way for highly efficient, low-power current-induced magnetization switching devices.